There are a plethora of outdoor activities enjoyed by active individuals. Mountaineering is one of the outdoor activities that is growing in popularity. Mountaineering activities may be as simple as climbing a mountain trail, or it may be take more involved forms such as free climbing. When free climbing, mountaineers use a variety of mechanical aids, such as pitons, bolts, chocks and stoppers, for anchoring themselves to a rock wall and the for the attachment of slings and the like.
Pitons are probably the mechanical climbing aid best known to the public. Pitons are steel spike like anchors that are forcefully driven, or hammered, into cracks in the rock face. Likewise, bolts are also forcefully driven into the rock face. The use of both has fallen into disfavor during recent years due to an anti-defacement ethic developing among mountaineers, and other wilderness users.
The use of removable chocks for climbing has evolved to replace the destructive practice of climbing with pitons and bolts. Chocks are typically wedge shaped devices used to anchor loops of cable to the rock face. There are two classifications of chocks, passive chocks and active chocks. Active chocks are mechanical devices employing numerous moving parts, each acting in cooperation with each other, to achieve the anchoring function. Examples of active chocking devices may be seen in the following U.S. Pat. Nos. 4,184,657; 4,491,291; 4,572,464; 4,586,686; 4,643,377; 4,643,378; 4,712,754; 4,834,327; and 4,923,160.
Passive chocks do not have moving parts and are primarily wedges or cans with a variety of different shapes. The first passive chocks were created by taking a regularly shaped hexagonal machine nut and looping a rope through the opening in the hexagonal axis. Opposed faces on the hexagonal nut were then wedged, with a horizontal hexagonal axis, between opposite rock faces of a crack. Because these first hexagonal chocks had a regular hexagonal shape they were only useful in cracks with a limited width variation. A different regular hexagonal chock size was needed for each different crack size. In practice, a rock face has a variety of different crack sizes. Thus, in order to cover the various crack sizes, one would have to carry an enormous suit of regular hexagonal nuts, a different nut for each different crack size. This is extremely heavy and burdensome to the climber.
Another passive chock is a simple tapered rectangular chock. The tapered rectangular chock has first and second rectangular bases with four trapezoidal walls extending between equivalent sides of the first and second bases, respectively. The design of this chock overcomes, at least in part, one of the limitations of the regular hexagonal chock discussed above. Each tapered rectangular chock may be used for two different sized cracks. This reduces by half the number of chocks needed to cover the range of crack sizes found on an actual rock wall. Each different width of the tapered rectangular chock is accessible by a 90 degree vertical rotation. This device is designed to be used in a vertical orientation, one in which the rectangular bases are horizontal and the axis between bases is vertical.
Yet another passive chock is disclosed in U.S. Pat. No. 4,081,241, by Burkey, which teaches a truncated trigonal pyramid having two substantially parallel bases each with three sides of unequal length. Three trapezoidal walls extend between corresponding sides of the two parallel bases. This device is designed to be used for three different sized cracks, each different size is accessible only by horizontal rotation of the truncated pyramid. Therefore, this device is designed to be used in a horizontal orientation, one in which the triangular bases are vertical, similar to the orientation of the regular hexagonal chock.
Vallence teaches, in U.S. Pat. No. 4,422,607, another rectangularly shaped passive climbing chock. The chock of this patent has two different sized rectangular bases and four walls with trapezoidal outline extending between the equivalent sides of two bases. Two of the walls have a concave and a convex configuration, respectively. The remaining two walls of the chock may be substantially flat, or, they may also be concave and convex, respectively. Thus, although this chock is used in a vertical attitude, it only provides for, at most, two different widths or orientations for use.
U.S. Pat. No. 3,948,485, by Chouinard et al., discloses a novel device with an irregular hexagonal horizontal cross section. The irregular hexagonal cross section of this device consists of three sets of opposed sides, a first set in which the opposed sides are parallel to each other, and a second and third set of opposed sides in which, in each set, the opposed sides have a dihedral angle of 10 degrees. This device further includes two end faces which also have a dihedral angle of 10 degrees. It is important to note that the horizontal axis of this device can never intersect any plane containing any of the six sides of this irregular hexagonal device, i.e., the six sides of this device are parallel to the horizontal axis of the device. Therefore, the horizontal axis only intersects the two end faces. Finally, this device requires two spaced apart circular passageways which extend between the pair of parallel faces. These circular passageways receive a rope (or cable) sling to which mountaineering devices can be attached.
Weight placed on the attached rope of the Chouinard device produces a rotational force about the horizontal axis of the device, thus camming the device into place.
While the above passive chocks are useful in themselves and in combination with each other, there is still a great need for a passive chock which has more than two useful orientations accessible by vertical rotation of the device.